Synthesis and photocatalytic activity of hydroxyapatite modified nitrogen-doped TiO2

TiO2 is a promising material as a photocatalyst for photodecomposition of hazardous organic pollutants under illumination, however, the low adsorption abilities, quantum yields and the lack of visible-light utilization hinder its practical application. In an attempt to extend light absorption of the TiO2-based photocatalyst towards the visible light range and improve its photocatalytic activity, a new photocatalyst, HAP-modified N-TiO2 (HAP-N-TiO2) was synthesized by a facile wet chemical method. The properties of HAP-N-TiO2 were investigated by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy. nitrogen adsorption-desorption isotherm measurement, UV-visible absorption spectroscopy, and photocurrent measurement. The photocatalytic activity of the samples was evaluated by the decomposition of gaseous acetone under visible light irradiation. The research results demonstrated that 10%-HAP-N-TiO2 sample shows the best photocatalytic activity, which is much superior to the other samples under visible light irradiation. The remarkable photocatalytic activity may arise from the synergism between adsorption on hydroxyapatite and photoactivity by titania. N-doping makes the composite also active under visible-light irradiation. (C) 2011 Elsevier B.V. All rights reserved.